It also relates to a device for applying said method.
It is known that in compressors, the oil conveyed lubrication circuits performs several main functions:
Firstly, a heat-bearing fluid function for dissipating the heat which results from the compression of the fluid, for example air;
Secondly, a sealing function, by constituting viscous seals at the various leakage paths and internal points of play; and
Thirdly, the actual lubrication function of the various components such as bearings, gear trains, friction seals and others.
With respect in particular to the heat-bearing function, it will easily be understood that the quantity of oil necessary for this purpose is a function of the quantity of heat to be dissipated, since the temperature of the air and oil mixture discharged by the compressor must be within a well-determined temperature range, with a view to preventing, firstly, condensation of water in the oil tank and secondly self-ignition of the air-oil mixture.
Thus when working under vacuum conditions the quantity of heat to be removed is less than when working under load and oil requirements are reduced.
The applicant has therefore sought to reduce the quantity of oil used under vacuum conditions, and to reduce the power then consumed by an even greater factor than in conventional compressors while using an oil circuit which is simple and highly reliable.